• 한국안전학회지
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• 제30권4호
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• pp.142-150
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• 2015

A portable recoilless guided missile generates a strong back blast and impulsive noise at the nozzle when it launches. In the case of indoor operations, the hazard of the blast noise from a recoilless weapon increases due to limited indoor spaces. Also, the noise levels determine the operational feasibility of a weapon; therefore, it is important to predict the blast noise levels distribution in the indoor space in advance. In addition, computational fluid dynamics (CFD) method generally used for fluid related simulations, requires high computing cost and time to simulate the whole domains. The domain includes both blast wave region and large and various indoor space region. Therefore, an efficient method for predicting the far-field noise level within a short time should be developed. This paper describes an analysis model for predicting the indoor noise distributions by considering the shape effect of the building within a short time. A new developed blast wave model was implemented using the noise source. Additionally, noise reflections at the closed surfaces such as walls and noise transmissions at the opened surfaces such as windows and doors were considered in calculating the noise levels. The predicted noise levels were compared with the experimental data obtained from the indoor launch test to validate the reliability of program.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.357.2-357
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• 2002

The blast vibration can generate occupants dissatisfy as well as damage of physics nearby building. Then blast vibration estimation issue important problems. But, now blast vibration prediction inside-outside country not established objective method according to blast number to express magnitude of vibration. In this study, Our propoes show our country problem of blast vibration about blast vibration measurement and this problems be able to find improve method. (omitted)

• 화약ㆍ발파
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• 제25권2호
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• pp.35-46
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• 2007

발파는 지반굴착 시 경제적으로 우수하고 과정이 간편하기 때문에 다양한 지반시설, 건축물에 널리리 적용된다. 발파에 의한 지반진동은 많은 실험과 연구로 제시되었지만 폭풍압에 의한 환경적 영향은 간과 하는 경향이 있다. 환경문제 대립의 경우에 지나치게 민감하고 논쟁의 여지가 있는 구조물에 대한 소음은 발파분야에서 무시되는 경향이 있다. 이에 비추어 이 연구는 폭풍압의 예상 진행방향을 조사하였다. 실제 폭풍압과 소음을 추정한 다음 회귀분석을 사용한 지발당 장약량에 기초를 두고 확실한 추정식을 만들었다. 추정식과 실제 결과치의 비교는 추정식의 타당성을 결정하는데 도움이 될 것이다.

• 화약ㆍ발파
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• 제22권3호
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• pp.85-95
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• 2004

국가의 발파진동과 소음에 대한 규제 기준은 공학적인 기술검증 절차에 의해 설정되어져야 한다. 발파진동에 의한 공해는 인체에 미치는 영향과 구조물이나 시설물에 미치는 영향이 전혀 다르게 나타나므로 각각의 특성에 맞는 기술적인 검증을 거쳐 규제기준이 설정되어져야한다. 현재 국가에서 규정하고 있는 발파진동에 대한 규제 기준은 환경부의 소음 진동 규제법과 건설교통부의 터널시방서의 발파진동허용기준이 전부이다. 환경부의 발파진동 규제기준은 사람의 주거환경을 대상으로 설정하였으므로 인체에 대한 발파진동의 반응현상을 근거한 선진국의 연구자료와 법규정 등을 인용하여 부분적으로는 문제점이 있으나 비교적 타당성이 있는 기준이 설정되었다고 사료된다. 그러나 건설교통부에서 발파진동 규제 기준으로 제시한 터널시방서의 발파진동허용기준은 발파공학적인 기술특성을 알지 못한 상태에서 부실하게 규제 기준을 만들어 정상적인 발파 공사를 방해할 뿐만 아니라 선진국과 국내에서 지극히 정상적으로 발파 공사를 수행하고 있는 공법까지도 발파진동허용기준에 저촉되어 공법을 폐기해야하는 문제점이 발생되었다. 본고는 건설교통부의 발파진동허용기준에 대한 문제점을 지적하고 합리적인 발파진동허용기준에 대한 방안을 제시하고자 한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.553-558
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• 2002

The blast vibration can generate occupants dissatisfy as well as damage of physics nearby building. Then blast vibration estimation issue important problems. But, now blast vibration prediction inside-outside country not established objective method to express magnitude of vibration according to blast number. In this study, Our propose show our country problem of blast vibration about blast vibration measurement and this problems be able to find improve method.

• 한국안전학회지
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• 제30권2호
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• pp.63-69
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• 2015

Recoilless weapons, which lead strong back blast and impulse noise more than 160 dB, have been used in compliance with the regulation of the safety zone for the safe operations. However, the safety zone regulations for the newly developed weapons should be prepared since the existing guidelines do not provide any information concerning the reason for the safety zone. In this study, the outdoor launch tests were performed to collect the data such as noise, pressure and temperature of the back blast. An assessment method using data obtained from launch tests has been proposed to determine the safety zone. The safety zone has been determined with consideration for the following criteria: Impulse noise, temperature and pressure of the back blast and blast angle. As a results, new safety zones for them have been established for the recoilless weapon developed by ADD (Agency for Defense Development). We expect that this research can be used as a guideline for establishing a new safety zone regulation of similar weapon to be developed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.875-878
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• 2006

In the case of a vibration sensitive equipment, it require a vibration free environment to provide its proper function, therefore, it is very important to predict precisely vibration environment of microelectronics production facility due to adjacent blast work. However, it is not easy to evaluate a quantitative vibration response of structure due blast because it can be determined by the characteristics of vibration sources, propagation through rock and soil and dynamic properties of building. In this paper, vibration influence evaluation of micro-electronic Production building induced from adjacent blast activity was performed by real measurement data obtained on ground and structure at same time. And blast vibration allowable limit on ground was supposed by measurement data analysis in order to avoid operation error of precision equipments

• 한국소음진동공학회논문집
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• 제19권10호
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• pp.1053-1061
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• 2009

The goal of this paper is to investigate the generation characteristics of the main impulsive noise sources generated by the supersonic flow discharging from a muzzle. For this, this paper investigates two fundamental mechanisms to sound generation in shocked flows: shock motion and shock deformation. Shock motion is modeled numerically by examining the interaction of a sound wave with a shock. The numerical approach is validated by comparison with results obtained by linear theory for a small disturbance case. Shock deformations are modeled numerically by examining the interaction of a vortex ring with a blast wave. A numerical approach of a dispersion-relation-preserving(DRP) scheme is used to investigate the sound generation and propagation by their interactions in near-field.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.485-492
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• 2005

Since blast-induced vibration may cause serious problem to the rock mass as well as the nearby structures, the prediction of blast-induced vibration and the stability evaluation must be performed before blasting activities. Dynamic analysis has been Increased recently in order to analyze the effect of the blast-induced vibration. Most of the previous studies, however, were based on the continuum analysis unable to consider rock joints which significantly affect the wave propagation and attenuation characteristics. They also adopted pressure curves estimated by theoretical or empirical equations as input detonation load, thus there were very difficult to reflect the characteristics of propagating media. In this study, therefore, we suggested a discontinuum dynamic analysis technique which uses velocity waveform obtained from a test blast as an input detonation load. A distinct element program, UDEC was used to consider the effect of rock joints. In order to verify the validity of proposed method, the test blast was simulated. The predicted results from the proposed method showed a good agreement with the measured vibration data from the test blast Through the dynamic numerical modelling on the planned road tunnel and slope, we evaluated the effect of blast-induced vibration and the stability of rock slope.

• 화약ㆍ발파
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• 제25권2호
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• pp.23-33
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• 2007

터널발파작업에 따른 발생소음의 크기는 소음 계측기의 특성상 근거리의의 측정이 불가하며 방음재질의 종류에 따라 소음저감 효과는 매우 다양한 차이를 나타낸다. 본 연구에서는 터널발파작업에 따라 설치되는 방음시설의 방음재질과 종류에 따른 소음저감 효과와 근거리에서의 소음예측방법을 조사하였다. 방음재질과 종류에 의한 소음과 주파수의 크기를 비교 분석하기 위하여 콘크리트 흄관 내에서 화공품의 일종인 폭죽으로 소음을 발생시키고 약 20여 종류의 방음재질을 설치하여 근거리에서 소음과 주파수의 크기를 측정 고찰하였다.